


It's Just the Two of Us

by FairyRose11



Category: Supernatural
Genre: M/M
Language: English
Status: Completed
Published: 2015-05-16
Updated: 2015-05-16
Packaged: 2018-03-30 19:48:27
Rating: Not Rated
Warnings: Graphic Depictions Of Violence, Major Character Death
Chapters: 1
Words: 4,259
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/3949447
Author URL: https://archiveofourown.org/users/FairyRose11/pseuds/FairyRose11
Summary: <blockquote class="userstuff">
              <p>In the end, it all happens just like Cain predicts, with one major difference: Dean never kills Castiel. Fast forward three hundred years, and the man who averted one apocalypse is now intent on bringing about a new end of days. There is really only one person who is capable of stopping him. It was always going to be Cas who had to watch Dean demolish the world, anyway.</p>
            </blockquote>





	It's Just the Two of Us

Angels are not supposed to have broken hearts.

Firstly, there’s the whole technical issue of the actual organ being responsible for pumping blood throughout the body, not emotions, something most angels will point out if the phrase “broken heart” is uttered in their immediate vicinity.

Secondly, angels are not supposed to love anyone or anything other than God, and it’s difficult to be broken-hearted over an eternal, and eternally absent, being.

Cas had smashed that particular rule, the “care not for humans” thing to smithereens, and all of the other angels knew it.

Still, Cas wished sometimes that he obeyed his brothers and sisters the first time. That he stayed the hell away from the Winchesters, because then he would never have had to endure losing them.

It has taken him far too long to see that the Dean Winchester he’d rebelled for, the Dean he cared about more than anyone else in the universe (possibly, even a tiny smidgen more than God Himself) was already dead.

Cas had not wept when Dean killed Crowley. Truth be told, the demon had had it coming for years. Temporary alliances aside, Crowley was the bad guy. Dean was supposed to kill him. That was the job.

Sam was another matter.

Cas had told Dean that when the Mark eventually took hold of him, everyone he loved would be dead (everyone but me, Cas thought). They wouldn’t have to see him like this, see him with the black eyes and the brutal smile, mowing down people like he hadn’t a care in the world.

Cas had never truly thought that Dean would kill Sam. It wasn’t possible. Over the years, Cas watched while Dean and Sam protected each other. They had a stronger bond than anyone else Cas had ever met. They loved each other, and it has taken Cas a long time to realize that love can blind you, can destroy you, leaving you pained and gasping for that last breath of air before you drown.

He hadn’t been fast enough. Cas had been stupid, and he hadn’t. Been. Fast. Enough. By the time he arrived… even centuries later, he could hardly bare to think of it. Blood everywhere. Sam Winchester’s body parts scattered on the floor. “So you can never bring him back,” Dean had said, sporting that smirk that stabbed Cas to the core of his non-existent soul.

He never did try to bring Sam back, not after that. Cas had stood there in the wreckage of what used to be his friend and known that it was kinder to let Sam stay dead. He also knew that he either had to kill Dean or die himself. Since the first one wasn’t an option, Cas stood there and let Dean come closer.

“Not going to even try?” Dean inquired.

“No point. You won’t die. You’re past saving, Dean. It doesn’t matter if I remove the Mark now. The man I knew is gone. Now get it over with.”

And of course Dean picked the cruelest option imaginable, because he was a demon now, and cruelty was as natural to him as breathing. He let Cas live.

Afterwards, Cas gathered the pieces of Sam’s body up for a funeral pyre. He cried, another new experience, Actual tears ran down his face and everything. He tried to say something, because that was what humans always seemed to do at funerals. The words wouldn’t come. Guilt and grief churned within him, and perhaps some of the guilt was because not all of the grief was for Sam.

Sam’s death was devastating, but it was looking into Dean’s eyes that caused Cas’ heart to break. They were black, and then they were pale green and so, so empty.

 

It’d been around three hundred years since then. Humanity had grown and changed.

The demon population could not say the same thing, not after the Demon Genocide.

As it turned out, being made into one of them has not endeared demonkind to Dean in the slightest. When the killings started, Cas felt a brief flicker of hope that he hated himself for later. The thought that maybe there was still a tiny bit of Dean left in the body that had become the vessel of the Mark.

The hope died when Dean began killing humans. At first, it was just criminals, something Cas could almost justify to himself. Then it became anyone who so much as rubbed Dean the wrong way on the street, and Cas stopped being able to justify.

Cas spent decades tracking Dean. Caught up with him a couple of times. All of the encounters ended with Cas bleeding and half-beaten to death. Never close enough to actually dying. Why wouldn’t Dean just kill him? For that matter, Cas often wondered why, even now, he couldn’t just kill himself.

Finally, Cas retreated to Heaven. Convinced himself that there was nothing more he could do. It was a feeble lie, but Cas had to believe it, because enduring the monster that had once been his dearest friend was too much for anyone to bear.

He did not return to Earth by choice; rather, Castiel was ordered to help with the Winchester problem.

Dean had started killing off the angels. Not just killing them; he’d capture one and torture it and send the other members of the garrison taunting photos before delivering the killing blow. The other members of the garrison would barge into whatever warehouse or hotel Dean was currently residing in, and they’d try to end him.

Everyone tried to kill Dean. Angels, demons, vampires, werewolves, witches, humans. It wouldn’t work. It never worked.

Cas was asked, and then ordered to find Dean, imprison him if nothing else. Never mind that Cas wearily told Hannah and the others that Dean would escape, because he always did. Cas had managed to trap him in a Devil’s Trap once, maybe… fifty years ago? At any rate, not even that could hold Dean. He’d simply become too powerful. Broken the circle with his mind and strode out like it was the most natural thing in the world.

It was just: find him Castiel. You know him better than anybody, and here Cas might have laughed, because he didn’t know Dean at all, not now.

 

He did try. He came close, once. May 2, 2215. Sam’s birthday. Cas did not find Dean so much as Dean finding him.

There was knock on the door to hotel room, and Cas opened it to find Dean staring calmly at him, as if nothing had ever changed. The First Blade was tucked into Dean’s belt, another thing that was all Cas’ fault. Not that it actually worked on Dean. Cas had rammed that blade into Dean’s just the summer of 2060, and Dean just popped it out of his body like it was a toothpick.

“Thanks Cas,” he’d said.

Cas still wasn’t entirely sure what Dean had done to himself in order to become so invulnerable, but he’d gathered that it involved dark magic and a whole lot of demonic souls.

“What do you want?” Cas said now. He held out his angel blade, though it wasn’t as if it would do anything.

“You’ve been hunting me,” Dean said. “I thought we should talk, Cas.”

If anyone had told Cas that he’d been sitting in a dirty bar with the man who used to be Dean Winchester, he would have stared for a moment before informing them that they were insane on a level that not even he had experienced.

Yet, here he was. Sitting in a dirty bar (and really, two hundred years and these places haven’t changed a bit) with the man who used to be Dean Winchester.

(Cas knew that he should really stop calling him Dean, stop thinking of him as Dean. He couldn’t help it. The name just kept slipping out).

“I’m going to ask again,” Cas said. “What do you want?”

Dean shrugged. He looked human, but Cas was an angel still. He could see the ruined soul underneath the flesh.

“It’s been a long time. I heard you gave up on me and went back to Heaven.”

“That’s true.”

Dean sighed. “See, this is why I knew it was okay to leave you still breathin’. Figured you’d finally learn that there’s nothing you can do to me.”

“Sam would never have accepted that.” Just stating a fact.

“No, he wouldn’t. Stubborn little punk.” Dean shifted in his seat. “Guess you know what day it is.”

“Sam’s birthday.” Cas looked at Dean, really looked at him. He seemed… almost sad. Melancholy. Back when Dean was human, he’d gotten like that sometimes. Tired and in pain, wanting to reach out to somebody, but never quite sure of how to do so, or whether he even deserved the comfort.

Cas did not expect to see such emotions from the Mark (and that’s all he is, Cas forces himself to remember, just the Mark wearing Dean’s face).

“Why did you kill him, Dean?”

Dean gazed at Cas, eyes normal for the moment. “You want the truth? Yeah, I was pissed with him, for Charlie and for everything. But that isn’t why I had to kill him. You hit the nail on the head, ya know? He never woulda stopped looking for a cure, never would have given up like you--” (Cas winced) “... and I was sick of it. All the stupid self-sacrifice that used to seem so important? Doesn’t mean anything, Cas. Just a couple of dicks who didn’t know how to let go.”

He leaned forward. “I let go, Cas. Finally. And you know what? He’s better off.”

Dean sat back, apparently satisfied with his explanation. Cas was still and cold. Dean glanced back at him.

“What, do you actually miss him?”

“Yes.” Cas did not add that he missed Dean even more. He was sure that Dean knew it, even so. “He was like a brother to me. And he was a better man than you are.”

“Don’t you think I know that?” Dean snarled, and Cas wondered if he’d pushed him too far at last. A couple of the other patrons looked up from their beers, raising their eyebrows at the two men who resembled humans.

“I will ask you one last time. What do you want?”

Dean flashed him a smile, and Cas marveled at the abrupt change of mood. “Maybe I just wanted to hang out with an old friend.”

“I doubt that.”

“Fine then, right to the point. I wanted to give you a heads up, Cas. Remember what you told me, two hundred years ago? When you tried to stop me the first time?”

Cas reached back through the years and found the memory. “I told you that centuries from then, everyone you loved would be dead, and it would be me who would have to watch you…” The force of the words struck him. “Oh.”

“... murder the world, that’s what you said. That’s what I’m gonna do, Cas. Not now, maybe not for another hundred years. I still like this world enough to let it stay standing for a while longer. Eventually, I’m gonna get bored, and that’s when I’m gonna start killing. You haven’t seen anything yet, Cas.”

“Why are you telling me this?”

“Always another question. I’m telling you because you’re gonna end up being the Luke to my Darth Vader.”

“...I don’t understand.”

“Thought Metatron downloaded Star Wars into your head back in the 21st century.”

“No, I meant… you want me to stop you?”

“No,” Dean said firmly. “I don’t plan on being brought back to the light side by the Power of Love, thanks. No, when I go nuclear, you’re gonna fight to save everyone. Not because I’m telling you to, but because that’s who you are. You’re gonna be humanity’s freakin’ guardian angel, and I’m gonna be the bad guy. That’s where this is all gonna end.”

Dean leaned back, and sipped his drink. “Till then, I thought we could keep on hanging out. Doesn’t always have to be a dive like this. We could go to the Grand Canyon, you’d like the Grand Canyon.”

Cas couldn’t think of anything to say for a long moment. Finally, he managed “ You want to be, what? Friends? What in the hell makes you think I would want to befriend you?”

Dean’s response was matter-of-fact. “You’re lonely. Thought we could be lonely together.”

“Well, you thought wrong.” Cas got up to leave. There was no point in staying. He didn’t know how to save Dean, or how to destroy him. Perhaps they were the same thing. “Is this why you’ve never attempted to kill me?”

“Maybe.”

“I hate you.”

“I know.”

 

Cas left Heaven soon after that. Some of the other angels were already trying to get him exiled, claiming that he had “conflicted loyalties.” Cas didn’t bother fighting it. He didn’t care enough to fight. He’d already fallen long ago. This was really nothing more than a formality.

 

After two years on Earth, while trying to scrape out a life of sorts, Cas found Dean again. And… they talked. Not especially civilized conversation. They could never trust each other, after all. Dean knew that Cas would annihilate him if he could, and Cas knew that Dean was a remorseless monster who gutted things for fun.

That aside, it was almost easy to fall back into old habits. Phone calls every so often, a couple of trips to the local crapsack restaurants (Dean hadn’t lost his taste for cheap food), even one (brief) road trip. Even after two hundred years, Dean’s baby was still running. Of course, he’d used God-knows-how-many spells in order to hold it together, replaced the gas tank with the solar batteries that were required by law now, and the wheels with hover mechanisms (nobody drove on the ground in the 23rd century).

Cas was almost happy, and at the same time, he was hurting every moment he spent with Dean. He was pretty sure that Dean knew that, too. He was even more certain that a part of Dean enjoyed causing that pain.

All this wasn’t to say that Cas just let Dean get away with everything. One of the ways that he rationalized his time with Dean was that it allowed him to prevent Dean from killing. Dean may have currently been one of the most powerful beings in the world, but Cas still had most of the abilities of a seraph. He couldn’t beat Dean, but he could fight. He could talk Dean down, or he could give someone time to run away (like Sam never could).

When Cas wasn’t occupying his time with Dean, he volunteered at hospitals. He helped with the old, and the blind. It was peaceful work, something Cas desperately needed.

Of course, he had to move on to a new area and a new job every decade or so, otherwise people would start to notice that he never aged. He once asked Dean if it was difficult for him, the endless life. Dean had chuckled and said that it was fricken’ awesome, thank you very much. Why waste time moaning when you could be off having fun? Anyway, Dean claimed, he didn’t care about anyone enough to miss them when they died of old age.

(Cas never asked if Dean cared about him. He didn’t think he would like the answer).

Then May 2, 2315 rolled around, and it all fell apart. Cas turned on the television, and the news was screaming about massacres occurring in nightclubs all around Kansas. Over one hundred dead already, many injured. The surviving witnesses seemed to be suffering from some sort of post-traumatic stress breakdown. They insisted that there had only been one attacker, a tall man in his mid-thirties. He’d sliced people up with some sort of bone-sword. Police were investigating, but they hadn’t been able to find any solid leads.

Dean had decided to start the end of the world on Sam’s birthday. Fitting.

Cas heard several different names used to describe Dean. The police force had nicknamed the illusive mass-murderer “The Black-Eyed Killer” from the witness descriptions (investigators mostly assumed that the killer wore contacts in order to generate more panic). Among the remaining angels (few and far between) he was dubbed “The Knight.” The dwindling monster community referred to him, half reverential and half terrified, as simply “The Hunter.” Actual hunters nicknamed him “The White Whale Demon,” as every hunter dreamed of sticking a harpoon through his chest, and none had ever succeeded.

So many titles, so many identities that all made up the same person. Someone that Cas despised, feared, and loved.

That was the irritating thing about human emotions, Cas decided. They just wouldn’t go away or change, no matter how much you wanted them to.

Dean had been right about the guardian angel thing. As civilizations all around the world were wiped out, Cas rose to the occasion. He fought. He found the dying, and he healed who he could. He slaughtered every one of the lesser monsters that Dean somehow convinced (or forced) to assist with destroying the world. Each time Cas killed one of Dean’s lackeys (and there were more than expected; even now, Dean Winchester still had that charisma that drew people in, made them want to die for him) he wished it was Dean.

At the same time, he wished that this was all a dream, just a dreadful nightmare that he’d had. All of it, becoming an angel again, Dean going dark, Sam’s death, none of it was real.

Cas knew what he would do if that were the case. He would get up and not care that he had a feeble human body that would decay over the next few decades. He would find Dean and tell him… tell him…

Tell him that he wasn’t alone. That he never needed to feel lost or alone, because he had Cas, who still loved him even when he was murdering… everything. Perhaps they would share a proper hug then (and Cas would hug back like he never had before), and things wouldn’t be perfect, but they would be better, because Cas would know just how lucky he was to have a Dean who loved him back.

But that was nothing more than a beautiful fantasy, and this world had no place for fantasies.

It took him a while to get started, but for the first time in centuries, Cas began searching in earnest for a way to kill Dean.

He’d checked every option: witchcraft, angelic magic, demonic magic, god spells, ancient weapons, even (and he could hardly believe that he was considering it) ritual sacrifice. Nothing was strong enough.

He’d even considered trying to open the Cage, but the risk of Michael or Lucifer escaping was too great.

It was the last thought that gave him the idea.

Cas made contact with a few hunters. There weren’t many of them nowadays: not enough things to hunt, once Dean was through with the monster population. He explained what he needed them to do, and told them, quite frankly, that the fate of the world rested in their hands and his. Then he began to search.

It took quite a while. Five years, actually. By that time, whole cities had been burnt to the ground. Millions dead. If the old Dean could see this, Cas thought, it would shatter him.

(Cas made himself stop thinking about the other Dean altogether. He couldn’t afford to feel any pity.)

All that was left was luring Dean into the trap. A couple of Cas’ hunter companions, along with the few angels still loyal to him offered to come. Cas declined the offer. He didn’t need to see anyone else die at Dean’s hands.

Dean hadn’t changed his phone number. The 24th century had developed phonic devices that could be implanted directly inside the ear, but Dean preferred the old handheld 22nd century model.

“Cas. Didn’t expect to hear from you.”

Cas had practiced this conversation over and over again. “I can’t take any more of it, Dean. I don’t want to have to keep on saving the world. I don’t want to fight you.”

A pause. “Is this you waving the white flag? You really think I’m gonna fall for that, Cas?”

“Just meet me. I want to talk to you in person. What’s the harm in it? I can’t kill you, you know that. If anything, I should be the one who’s afraid.”

“Are you?” Dean inquired. Cas had heard that in order to lie convincingly, you added a bit of truth into the lie.

“Yes.”

Cas could practically see Dean’s smile. “I’ll see you soon.”

 

They met in the middle of an empty field in Iowa. Cas had deliberately picked a location with no one else around who could be hurt.

“Well, aren’t you a sight for sore eyes,” Dean drawled, climbing out of the ancient Impala that would outlive them both.

“I believe your Lord of the Rings had an appropriate quote for our situation. We’re here, at the end of all things. Just the two of us.” Cas looked at him. “I used to love you, you know. Back when you were worth it.” A statement intended to jab, if nothing else. It didn’t matter that Cas still felt something for the man who had nearly succeeded in destroying everything. Love was not the same as affection, and Cas felt absolutely no regret for what he was about to do.

“Is that so? Friend love, or gooey hallmark romantic stuff?”

“Doesn’t matter now.”

“I guess it doesn’t. Was this what you wanted to tell me?”

“No,” Cas said. “I just thought you should know.” With that, he sprung the trap. Dean jumped in surprise as Cas lunged forward and grabbed the First Blade. Dean clutched it automatically, eyes going demon-black as he shoved it threateningly at Cas’ body. What he didn’t expect was for Cas to lean forward, and keep moving as the Blade tore through his chest.

Dean yanked the Blade out of Cas, staring. “I gotta admit, I didn’t see that one--” With that, the ground beneath Dean’s feet opened. Something old and impossibly powerful seized him and held him, despite Dean’s attempts to escape. Still clutching the blade in one hand, Dean clutched at the crumbling earth, while the… whatever it was tried to drag him down.

Cas propped himself up painfully and smiled at Dean. “It’s a cage,” he said conversationally. “Like Lucifer’s. It’s made from a spell that existed even before that damned Mark. The original spell that God used to create the Cage in Hell. Of course, I’m not God. Can’t make a prison without a price. My lifeblood opens the gate. My lifeblood seals it. You can’t escape, Dean.”

The words were accompanied by agonized gasping. Cas forced his vessel to not heal itself, to leave the gaping wound in place. He’d lived long enough. Time to make his death useful.

Dean’s face went from horrified to enraged to determined. “Nah, Cas. I’m not goin’ in there.”

“You… don’t have… a choice. I die… you get sucked in.”

While Cas was talking, Dean had been dragged even further down. Only his head, shoulders and arms were visible now.

“That’s the thing, Cas. There is one way I can die,” Dean choked out through gritted teeth.

“What’s that?”

“I kill myself,” Dean said flatly, and his face began to split apart. Blood dripped from the cuts that opened in his face and arms. The wounds widened, changing from thin scratches to deep wounds in seconds.

“I’d rather die than spend eternity in a pit,” Dean gasped. Cas took a moment to process that of course Dean had the strength to kill himself, he’d just never wanted to. Cain had never realized it: no weapon could destroy the Mark, but if you were powerful enough, you could simply will your body to cease functioning, and even the Mark would have to obey. A last act of destruction, turned on yourself.

“Where,” Dean whispered on one of his last breaths, “Do you think we’ll go?”

There was no hope of Dean going to Heaven. His soul was too polluted for that. No hope of hell either, or Purgatory. No one knew where demons went when they died. No one knew where angels went when they died. Perhaps they were going to the same place.

“I don’t know,” Cas murmured, feeling the blood trickle down his body. Too late to do anything about it now, the Blade’s energy was imbedded inside him. And yet, somehow he didn’t feel like he had thrown away his life for nothing. He’d forced Dean to make the choice, in the end. He’d saved the world. That had to count for something, right?

“Cas,” Dean said and Cas hauled himself over to Dean’s side, because what could either of them do to each other, anymore? Dean’s face was a bloody mess. His eyes were green.

Dean reached out one arm to wrap around Cas’ neck, and Cas wasn’t sure if it was supposed to be a hug or a chokehold. Maybe both.

“Goodbye, Dean.” As he said it, Dean’s face went blank and his arms went slack. Later, someone would stumble upon their bodies and wonder how in the hell they’d ended up here.

Cas let himself fall forward, half covering Dean’s corpse.

He smiled as the blackness took him.


End file.
